fix run card finding for FRVZ VH setups
Description of bug
FRVZ VH setups (500765-500779) try to locate run card and parameter card in a buggy way (searching in the wrong path, causing the grid jobs to crash). cc/ @lsabetta
Changes introduced
fixed the run/parameter card finding
Tests
Issues resolved
Needed to resolve ATLMCPROD-8530
Closes #